In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200831103542.305571-34-allen.lkml@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
On prep, a spin lock is taken and the next entry in the circular buffer
is filled. On submit, the valid bit is set in the hardware descriptor
and the lock is released.
The DMA engine is started (if it's not already running) when the client
calls dma_async_issue_pending().
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20200103212021.2881-4-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Allocate DMA coherent memory for the ring of DMA descriptors and
program the appropriate hardware registers.
A tasklet is created which is triggered on an interrupt to process
all the finished requests. Additionally, any remaining descriptors
are aborted when the hardware is removed or the resources freed.
Use an RCU pointer to synchronize PCI device unbind.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20200103212021.2881-3-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Some PLX Switches can expose DMA engines via extra PCI functions
on the upstream port. Each function will have one DMA channel.
This patch is just the core PCI driver skeleton and dma
engine registration.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20200103212021.2881-2-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
